Defines the difference between an amateur who knows what their life calling is but is afraid to do it, so either spends their time tweeting and myriad other ways to hide from their vocation and the professional who not only knows what their mission in life is but embraces and pursues it and makes it happens. He/She must deal with the same Resistance (Pressfield's catch-all term for the malignant force inside all of us that does all it can to prevent us from amounting to anything) every day as the amateur does, but the pro defeats it, while the amateur does not. I am still working on Turning Pro myself. If you want to as well, read Pressfield's books starting with The War of Art, then Do the Job, and then this. The other two I consider better, but Pro contains valuable information that you will not want to miss after reading the others. God bless Steven Prressfield for exposing Resistance and showing us how to fight it and defeat it!